1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright (C) 2006-2007 Red Hat, Inc.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
18 * Boston, MA 02111-1307, USA.
20 * Author: Alexander Larsson <alexl@redhat.com>
26 #include "gfilemonitor.h"
27 #include "gioenumtypes.h"
34 typedef struct _FileChange FileChange;
35 static void file_change_free (FileChange *change);
38 * SECTION:gfilemonitor
39 * @short_description: File Monitor
42 * Monitors a file or directory for changes.
44 * To obtain a #GFileMonitor for a file or directory, use
45 * g_file_monitor(), g_file_monitor_file(), or
46 * g_file_monitor_directory().
48 * To get informed about changes to the file or directory you are
49 * monitoring, connect to the #GFileMonitor::changed signal. The
50 * signal will be emitted in the <link
51 * linkend="g-main-context-push-thread-default">thread-default main
52 * context</link> of the thread that the monitor was created in
53 * (though if the global default main context is blocked, this may
54 * cause notifications to be blocked even if the thread-default
55 * context is still running).
58 G_LOCK_DEFINE_STATIC(cancelled);
67 guint32 last_sent_change_time; /* 0 == not sent */
68 guint32 send_delayed_change_at; /* 0 == never */
69 guint32 send_virtual_changes_done_at; /* 0 == never */
72 struct _GFileMonitorPrivate {
76 /* Rate limiting change events */
77 GHashTable *rate_limiter;
80 GSource *pending_file_change_source;
81 GSList *pending_file_changes; /* FileChange */
84 guint32 timeout_fires_at;
86 GMainContext *context;
95 /* work around a limitation of the aliasing foo */
98 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT)
101 g_file_monitor_set_property (GObject *object,
106 GFileMonitor *monitor;
108 monitor = G_FILE_MONITOR (object);
112 case PROP_RATE_LIMIT:
113 g_file_monitor_set_rate_limit (monitor, g_value_get_int (value));
117 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
123 g_file_monitor_get_property (GObject *object,
128 GFileMonitor *monitor;
129 GFileMonitorPrivate *priv;
131 monitor = G_FILE_MONITOR (object);
132 priv = monitor->priv;
136 case PROP_RATE_LIMIT:
137 g_value_set_int (value, priv->rate_limit_msec);
142 g_value_set_boolean (value, priv->cancelled);
143 G_UNLOCK (cancelled);
147 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
152 #define DEFAULT_RATE_LIMIT_MSECS 800
153 #define DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS 2
155 static guint signals[LAST_SIGNAL] = { 0 };
158 rate_limiter_free (RateLimiter *limiter)
160 g_object_unref (limiter->file);
161 g_slice_free (RateLimiter, limiter);
165 g_file_monitor_finalize (GObject *object)
167 GFileMonitor *monitor;
169 monitor = G_FILE_MONITOR (object);
171 if (monitor->priv->timeout)
173 g_source_destroy (monitor->priv->timeout);
174 g_source_unref (monitor->priv->timeout);
177 g_hash_table_destroy (monitor->priv->rate_limiter);
179 g_main_context_unref (monitor->priv->context);
180 g_mutex_clear (&monitor->priv->mutex);
182 G_OBJECT_CLASS (g_file_monitor_parent_class)->finalize (object);
186 g_file_monitor_dispose (GObject *object)
188 GFileMonitor *monitor;
189 GFileMonitorPrivate *priv;
191 monitor = G_FILE_MONITOR (object);
192 priv = monitor->priv;
194 if (priv->pending_file_change_source)
196 g_source_destroy (priv->pending_file_change_source);
197 g_source_unref (priv->pending_file_change_source);
198 priv->pending_file_change_source = NULL;
200 g_slist_free_full (priv->pending_file_changes, (GDestroyNotify) file_change_free);
201 priv->pending_file_changes = NULL;
203 /* Make sure we cancel on last unref */
204 g_file_monitor_cancel (monitor);
206 G_OBJECT_CLASS (g_file_monitor_parent_class)->dispose (object);
210 g_file_monitor_class_init (GFileMonitorClass *klass)
212 GObjectClass *object_class;
214 object_class = G_OBJECT_CLASS (klass);
215 object_class->finalize = g_file_monitor_finalize;
216 object_class->dispose = g_file_monitor_dispose;
217 object_class->get_property = g_file_monitor_get_property;
218 object_class->set_property = g_file_monitor_set_property;
221 * GFileMonitor::changed:
222 * @monitor: a #GFileMonitor.
224 * @other_file: (allow-none): a #GFile or #NULL.
225 * @event_type: a #GFileMonitorEvent.
227 * Emitted when @file has been changed.
229 * If using #G_FILE_MONITOR_SEND_MOVED flag and @event_type is
230 * #G_FILE_MONITOR_EVENT_MOVED, @file will be set to a #GFile containing the
231 * old path, and @other_file will be set to a #GFile containing the new path.
233 * In all the other cases, @other_file will be set to #NULL.
236 g_signal_new (I_("changed"),
239 G_STRUCT_OFFSET (GFileMonitorClass, changed),
243 G_TYPE_FILE, G_TYPE_FILE, G_TYPE_FILE_MONITOR_EVENT);
245 g_object_class_install_property (object_class,
247 g_param_spec_int ("rate-limit",
249 P_("The limit of the monitor to watch for changes, in milliseconds"),
251 DEFAULT_RATE_LIMIT_MSECS,
253 G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
255 g_object_class_install_property (object_class,
257 g_param_spec_boolean ("cancelled",
259 P_("Whether the monitor has been cancelled"),
262 G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
266 g_file_monitor_init (GFileMonitor *monitor)
268 monitor->priv = g_file_monitor_get_instance_private (monitor);
269 monitor->priv->rate_limit_msec = DEFAULT_RATE_LIMIT_MSECS;
270 monitor->priv->rate_limiter = g_hash_table_new_full (g_file_hash, (GEqualFunc)g_file_equal,
271 NULL, (GDestroyNotify) rate_limiter_free);
272 monitor->priv->context = g_main_context_ref_thread_default ();
273 g_mutex_init (&monitor->priv->mutex);
277 * g_file_monitor_is_cancelled:
278 * @monitor: a #GFileMonitor
280 * Returns whether the monitor is canceled.
282 * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
285 g_file_monitor_is_cancelled (GFileMonitor *monitor)
289 g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
292 res = monitor->priv->cancelled;
293 G_UNLOCK (cancelled);
299 * g_file_monitor_cancel:
300 * @monitor: a #GFileMonitor.
302 * Cancels a file monitor.
304 * Returns: %TRUE if monitor was cancelled.
307 g_file_monitor_cancel (GFileMonitor* monitor)
309 GFileMonitorClass *klass;
311 g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
314 if (monitor->priv->cancelled)
316 G_UNLOCK (cancelled);
320 monitor->priv->cancelled = TRUE;
321 G_UNLOCK (cancelled);
323 g_object_notify (G_OBJECT (monitor), "cancelled");
325 klass = G_FILE_MONITOR_GET_CLASS (monitor);
326 return (* klass->cancel) (monitor);
330 * g_file_monitor_set_rate_limit:
331 * @monitor: a #GFileMonitor.
332 * @limit_msecs: a non-negative integer with the limit in milliseconds
333 * to poll for changes
335 * Sets the rate limit to which the @monitor will report
336 * consecutive change events to the same file.
339 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
342 GFileMonitorPrivate *priv;
344 g_return_if_fail (G_IS_FILE_MONITOR (monitor));
345 g_return_if_fail (limit_msecs >= 0);
347 priv = monitor->priv;
348 if (priv->rate_limit_msec != limit_msecs)
350 monitor->priv->rate_limit_msec = limit_msecs;
351 g_object_notify (G_OBJECT (monitor), "rate-limit");
358 GFileMonitorEvent event_type;
362 file_change_free (FileChange *change)
364 g_object_unref (change->child);
365 if (change->other_file)
366 g_object_unref (change->other_file);
368 g_slice_free (FileChange, change);
372 emit_cb (gpointer data)
374 GFileMonitor *monitor = G_FILE_MONITOR (data);
375 GSList *pending, *iter;
377 g_mutex_lock (&monitor->priv->mutex);
378 pending = g_slist_reverse (monitor->priv->pending_file_changes);
379 monitor->priv->pending_file_changes = NULL;
380 if (monitor->priv->pending_file_change_source)
382 g_source_unref (monitor->priv->pending_file_change_source);
383 monitor->priv->pending_file_change_source = NULL;
385 g_mutex_unlock (&monitor->priv->mutex);
387 g_object_ref (monitor);
388 for (iter = pending; iter; iter = iter->next)
390 FileChange *change = iter->data;
392 g_signal_emit (monitor, signals[CHANGED], 0,
393 change->child, change->other_file, change->event_type);
394 file_change_free (change);
396 g_slist_free (pending);
397 g_object_unref (monitor);
403 emit_in_idle (GFileMonitor *monitor,
406 GFileMonitorEvent event_type)
410 GFileMonitorPrivate *priv;
412 priv = monitor->priv;
414 change = g_slice_new (FileChange);
416 change->child = g_object_ref (child);
418 change->other_file = g_object_ref (other_file);
420 change->other_file = NULL;
421 change->event_type = event_type;
423 g_mutex_lock (&monitor->priv->mutex);
424 if (!priv->pending_file_change_source)
426 source = g_idle_source_new ();
427 priv->pending_file_change_source = source;
428 g_source_set_priority (source, 0);
430 /* We don't ref monitor here - instead dispose will free any
433 g_source_set_callback (source, emit_cb, monitor, NULL);
434 g_source_attach (source, monitor->priv->context);
436 /* We reverse this in the processor */
437 priv->pending_file_changes = g_slist_prepend (priv->pending_file_changes, change);
438 g_mutex_unlock (&monitor->priv->mutex);
442 get_time_msecs (void)
444 return g_get_monotonic_time () / G_TIME_SPAN_MILLISECOND;
448 time_difference (guint32 from, guint32 to)
455 /* Change event rate limiting support: */
458 new_limiter (GFileMonitor *monitor,
461 RateLimiter *limiter;
463 limiter = g_slice_new0 (RateLimiter);
464 limiter->file = g_object_ref (file);
465 g_hash_table_insert (monitor->priv->rate_limiter, file, limiter);
471 rate_limiter_send_virtual_changes_done_now (GFileMonitor *monitor,
472 RateLimiter *limiter)
474 if (limiter->send_virtual_changes_done_at != 0)
476 emit_in_idle (monitor, limiter->file, NULL,
477 G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
478 limiter->send_virtual_changes_done_at = 0;
483 rate_limiter_send_delayed_change_now (GFileMonitor *monitor,
484 RateLimiter *limiter,
487 if (limiter->send_delayed_change_at != 0)
489 emit_in_idle (monitor,
491 G_FILE_MONITOR_EVENT_CHANGED);
492 limiter->send_delayed_change_at = 0;
493 limiter->last_sent_change_time = time_now;
500 GFileMonitor *monitor;
504 calc_min_time (GFileMonitor *monitor,
505 RateLimiter *limiter,
514 if (limiter->last_sent_change_time != 0)
516 /* Set a timeout at 2*rate limit so that we can clear out the change from the hash eventually */
517 expire_at = limiter->last_sent_change_time + 2 * monitor->priv->rate_limit_msec;
519 if (time_difference (time_now, expire_at) > 0)
522 *min_time = MIN (*min_time,
523 time_difference (time_now, expire_at));
527 if (limiter->send_delayed_change_at != 0)
530 *min_time = MIN (*min_time,
531 time_difference (time_now, limiter->send_delayed_change_at));
534 if (limiter->send_virtual_changes_done_at != 0)
537 *min_time = MIN (*min_time,
538 time_difference (time_now, limiter->send_virtual_changes_done_at));
545 foreach_rate_limiter_fire (gpointer key,
549 RateLimiter *limiter = value;
550 ForEachData *data = user_data;
552 if (limiter->send_delayed_change_at != 0 &&
553 time_difference (data->time_now, limiter->send_delayed_change_at) == 0)
554 rate_limiter_send_delayed_change_now (data->monitor, limiter, data->time_now);
556 if (limiter->send_virtual_changes_done_at != 0 &&
557 time_difference (data->time_now, limiter->send_virtual_changes_done_at) == 0)
558 rate_limiter_send_virtual_changes_done_now (data->monitor, limiter);
560 return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
564 rate_limiter_timeout (gpointer timeout_data)
566 GFileMonitor *monitor = timeout_data;
570 data.min_time = G_MAXUINT32;
571 data.monitor = monitor;
572 data.time_now = get_time_msecs ();
573 g_hash_table_foreach_remove (monitor->priv->rate_limiter,
574 foreach_rate_limiter_fire,
577 /* Remove old timeout */
578 if (monitor->priv->timeout)
580 g_source_destroy (monitor->priv->timeout);
581 g_source_unref (monitor->priv->timeout);
582 monitor->priv->timeout = NULL;
583 monitor->priv->timeout_fires_at = 0;
586 /* Set up new timeout */
587 if (data.min_time != G_MAXUINT32)
589 source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
590 g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
591 g_source_attach (source, monitor->priv->context);
593 monitor->priv->timeout = source;
594 monitor->priv->timeout_fires_at = data.time_now + data.min_time;
601 foreach_rate_limiter_update (gpointer key,
605 RateLimiter *limiter = value;
606 ForEachData *data = user_data;
608 return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
612 update_rate_limiter_timeout (GFileMonitor *monitor,
618 if (monitor->priv->timeout_fires_at != 0 && new_time != 0 &&
619 time_difference (new_time, monitor->priv->timeout_fires_at) == 0)
620 return; /* Nothing to do, we already fire earlier than that */
622 data.min_time = G_MAXUINT32;
623 data.monitor = monitor;
624 data.time_now = get_time_msecs ();
625 g_hash_table_foreach_remove (monitor->priv->rate_limiter,
626 foreach_rate_limiter_update,
629 /* Remove old timeout */
630 if (monitor->priv->timeout)
632 g_source_destroy (monitor->priv->timeout);
633 g_source_unref (monitor->priv->timeout);
634 monitor->priv->timeout_fires_at = 0;
635 monitor->priv->timeout = NULL;
638 /* Set up new timeout */
639 if (data.min_time != G_MAXUINT32)
641 source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
642 g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
643 g_source_attach (source, monitor->priv->context);
645 monitor->priv->timeout = source;
646 monitor->priv->timeout_fires_at = data.time_now + data.min_time;
651 * g_file_monitor_emit_event:
652 * @monitor: a #GFileMonitor.
654 * @other_file: a #GFile.
655 * @event_type: a set of #GFileMonitorEvent flags.
657 * Emits the #GFileMonitor::changed signal if a change
658 * has taken place. Should be called from file monitor
659 * implementations only.
661 * The signal will be emitted from an idle handler (in the <link
662 * linkend="g-main-context-push-thread-default">thread-default main
666 g_file_monitor_emit_event (GFileMonitor *monitor,
669 GFileMonitorEvent event_type)
671 guint32 time_now, since_last;
673 RateLimiter *limiter;
675 g_return_if_fail (G_IS_FILE_MONITOR (monitor));
676 g_return_if_fail (G_IS_FILE (child));
678 limiter = g_hash_table_lookup (monitor->priv->rate_limiter, child);
680 if (event_type != G_FILE_MONITOR_EVENT_CHANGED)
684 rate_limiter_send_delayed_change_now (monitor, limiter, get_time_msecs ());
685 if (event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT)
686 limiter->send_virtual_changes_done_at = 0;
688 rate_limiter_send_virtual_changes_done_now (monitor, limiter);
689 update_rate_limiter_timeout (monitor, 0);
691 emit_in_idle (monitor, child, other_file, event_type);
695 /* Changed event, rate limit */
696 time_now = get_time_msecs ();
701 since_last = time_difference (limiter->last_sent_change_time, time_now);
702 if (since_last < monitor->priv->rate_limit_msec)
704 /* We ignore this change, but arm a timer so that we can fire it later if we
705 don't get any other events (that kill this timeout) */
707 if (limiter->send_delayed_change_at == 0)
709 limiter->send_delayed_change_at = time_now + monitor->priv->rate_limit_msec;
710 update_rate_limiter_timeout (monitor, limiter->send_delayed_change_at);
716 limiter = new_limiter (monitor, child);
720 emit_in_idle (monitor, child, other_file, event_type);
722 limiter->last_sent_change_time = time_now;
723 limiter->send_delayed_change_at = 0;
724 /* Set a timeout of 2*rate limit so that we can clear out the change from the hash eventually */
725 update_rate_limiter_timeout (monitor, time_now + 2 * monitor->priv->rate_limit_msec);
728 /* Schedule a virtual change done. This is removed if we get a real one, and
729 postponed if we get more change events. */
731 limiter->send_virtual_changes_done_at = time_now + DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS * 1000;
732 update_rate_limiter_timeout (monitor, limiter->send_virtual_changes_done_at);